We purchased F1CSB-100G for calibration of the balance. I was wondering if it would arrive in a plastic case, etc., but it was a blister pack devised so that scratches etc. will not stick. It seems that some kind of equipment is required separately for storage because it does not look like airtightness to prevent moisture etc. Also, in selecting the weights, the manufacturer Taisho Balance (Shinko Electronics) published public commentary on YouTube about the calibration of the balance, so I thought it was okay if I had chosen after watching it.